Cows have 4 bellies.

The cow's belly is the cow's stomach, and cows have 4 stomachs, which are rumen, reticulum, flap stomach, and wrinkled stomach. The rumen, reticulum, flap stomach has no gastric glands, does not secrete gastric juice, its function is similar to the esophagus. The crumpled stomach, on the other hand, has gastric glands that secrete digestive juices, similar to the human stomach, and is also called the true stomach. Because of their different structures, the 4 stomachs have different tastes.

The rumen stomach is is the cow grass tripe, which has pimple-like protrusions on its surface and a tougher texture, making it suitable for use in stews, blanquettes and cold dishes.

Expanded information:

Beef tripe digestive principle:

In ruminants, they are not directly in the feed nutrients through their own digestion and absorption, no matter what type of nutrients are first fermented by rumen microorganisms. The fermentation process ultimately produces organic acids and some primary fatty acids that can be absorbed by the rumen as energy for their metabolism.

It can be said that the rumen microorganisms' bacterial proteins, saccharides and lipids are the most important and direct source of nutrients for ruminants.

Baidu Encyclopedia-Beef Tripe